FIG. 1 shows an architecture diagram of a current 3GPP Evolved Packet System (EPS). The EPS network architecture in a non-roaming scene shown in FIG. 1 includes an Evolved Universal Terrestrial Radio Access Network (E-UTRAN), a Mobility Management Entity (MME), a Serving Gateway (S-GW), a Packet Data Network Gateway (P-GW, also called PDN GW), a Home Subscriber Server (HSS), a Policy and Charging Rules Function (PCRF) and other support nodes.
The PCRF is the core of Policy and Charging Control (PCC) and is responsible for making policies and making charging rules. The PCRF provides network control rules which are based on service data stream, wherein the network control includes the detection, gating control, Quality of Service (QoS) control of the service data stream, the charging rules based on data stream and so on. The PCRF sends the policy and charging rules made by the PCRF itself to a Policy and Charging Enforcement Function (PCEF) to execute, meanwhile the PCRF has to guarantee the consistency between the rules and the subscription information of a user. The basis for the PCRF to make policy and charging rules includes: acquiring information related to service from Application Function (AF), acquiring the policy and charging control subscription information of a user from a Subscription Profile Repository (SPR), and acquiring network information related to bearer from the PCEF.
The EPS supports the interconnection with a non-3GPP system, which is implemented through S2a/b/c interfaces, wherein the P-GW serves as an anchor between the 3GPP system and the non-3GPP system. As shown in FIG. 1, the non-3GPP system is divided into trusted non-3GPP IP access and untrusted non-3GPP IP access, wherein the trusted non-3GPP IP access is connected directly to the P-GW via the S2a interface; while the untrusted non-3GPP IP access needs to be connected to the P-GW through an Evolved Packet Data Gateway (ePDG). The interface between the ePDG and the P-GW is the S2b interface, and Internet Protocol Security (IPSec) is adopted between the User Equipment (UE) and the ePDG to perform encryption protection on signalling and data. The S2c interface provides user-plane-related control and mobility support between the UE and the P-GW, wherein the supported mobility management protocol is Mobile IPv6 support for dual stack Hosts and Routers (DSMIPv6).
At present, many operators focus on Fixed Mobile Convergence (FMC) and research the intercommunication between 3GPP and BBF. For the scene that a user accesses a mobile core network through the BBF (that is, fixed broadband access network), it is needed to guarantee the QoS on the entire transmission path of data (the data would be transmitted through the fixed network and the mobile network). In the conventional art, interaction is implemented through the PCRF and a Broadband Policy Control Framework (BPCF) in the BBF access (that is, fixed broadband access network), so as to realize QoS guarantee. The BPCF is the policy control framework in the fixed broadband access network. For a resource request message from the PCRF, the BPCF performs resource admission control according to the network policy and subscription information of the fixed broadband access network, or forwards the resource request message to other network elements (for example, Broadband Network Gateway (BNG)) of the fixed broadband access network), and then this network element performs resource admission control (that is to say, the BPCF delegates other network elements to perform resource admission control). For example, when a UE accesses a 3GPP core network through a Wide Local Area Network (WLAN), in order to guarantee that the total bandwidth of the services accessed by all UEs which access the core network through one WLAN access line does not exceed the bandwidth of this line (for example, subscribed bandwidth or maximum physical bandwidth supported by this line), the PCRF needs to interact with the BPCF when performing QoS authorization, so that the fixed broadband access network performs the resource admission control. During specific implementation, the PCRF provides QoS rules for the BPCF and the fixed broadband access network performs admission control according to the QoS rules.
FIG. 2 shows a diagram illustrating the architecture in which a UE accesses a 3GPP core network through a fixed broadband access network according to the conventional art.
As shown in FIG. 2, the fixed broadband access network serves as the untrusted non-3GPP access. In the architecture shown in FIG. 2, after the UE is accessed to the fixed broadband access network, a Broadband Remote Access Server (BRAS)/BNG would perform 3GPP-based access authentication, meanwhile the BPCF of the BBF actively initiates an S9* session to interact with the PCRF of the 3GPP. Thus, the PCRF can interact with the BPCF when performing QoS authorization; and then the BPCF performs the resource admission control or delegates other network elements of the fixed broadband access network to perform the resource admission control.
However, in some scenes, the fixed broadband access network can not always sense the access of UE, or the fixed broadband access network does not support the 3GPP-based access authentication. In this case, the BPCF can not initiate the S9* session actively and thus can not implement the QoS control on the access of UE.